The more you walk the day of the race the better off you are. I had a ROUGH marathon last year as I have shared. I walked to the monorail after the race, then back to my room in the hotel, showered and off to AK I went. I was moving slow for sure but the next day I wasn't very sore at all. My swelling hung around for 9-12 months. I didn't even get all the feeling back in the left side of my foot for about 18 months. I didn't realize until I went through this that it is a pretty serious surgery. Even the new doctor I saw said the same thing. There are tons of nerves involved and everything. @DopeyBadger is the expert on this stuff on this thread. He will probably offer more of an informed opinion but what I would say is, if you are doing the challenge, you need at least 4 days of running a week and two days need to be back to back to try and simulate what you will go through for the actual race. If you aren't used to running high mileage or back to back days then doing it the first time at race weekend you might be sore, or struggle. I would get up at 5:00 instead of 5:20 and get the extra mileage in on those days. I would also buy a headlamp to run the night your daughter is dancing. My headlamp is heavy duty, and as bright as a car headlight, and I think it was $45. I also got a light up vest to wear to make myself easier to see. I can provide links to either if interested. The question you need to ask yourself is, how bad do I want this for myself. If you want badly then there is always as solution to accomplish your goals and we would all be happy to help with suggestions.